Automatically-operating switch for electric circuits.



F. KUHN. AUTOMATICALLY OPERATING SWITGH FOB. ELECTRIC GIROUITS.-

APPLIOATION FILED mm, 1912.

. 1,060,987, Patented May 6, 1913.

FRANK KUHN, 0F DETROIT, MICHIGAN.

AUTOMATICALLY-OPERATING SWITCH FOR ELECTRIC CIRCUITS.

Specification of Letters latent.

Patented May 6, 1913.

Application filed May 4, 1912. Serial No. 695,038.

To all whom, it may concern:

Be it known that I, F RANK. KUHN, a citizen of the United States of America, residing at Detroit, in the county of \Vayne and State of l\lichigan, have invented certain new and useful Improvements in Automatically-Operating Switches for Electric Circuits, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to automatic switches for controlling electric circuits, being more particularly designed for use in connection wit-h electric heaters.

It is the object of the invention to avoid danger by automatically opening the heater consists in the construction as hereinafter set forth.

- In the drawings-Figure 1 is a sectional elevation of the automatic switch mechanism; Fig. 2 is a plan view of a portion thereof.

A is a controller switch of any suitable construction, preferably a double blade knife switch, B is tie base upon which the switch is mounted, and C is a resilient arm engaging a bearing D upon the switch and operat ing to normally hold the switch in open position.

E is a latch dctcnt for engaging the arm C in its retracted or tensioned position into which position it is forced by the closing of the switch A.

To pioride for the opening of the switch after the desired interval, a time mechanism of any suitable mechanical construction is employed. Inasmuch however, as there always danger of sin-h a mechanism bcconr in; inoperulive and which would permit the switch to remain closed, I have provided means for automatically opening the switch not dependent upon the operativcncss of the mechanism. This preferably consists in an electromagnet F, the armature G of which is connected with the latch detent E, being pivotally supported at H upon abracket I and being held normally in latching position by a spring J. The magnet F is included in an electric circuit which when closed to energize the magnet, will disengage the latch E and permit the spring C to open the switch A. The circuit for the magnet F is controlled by a time switch including a clock mechanism K and a retarding device such as the fan L. g

M is a contact member which is slowly moved by the mechanism as for instancethrough the medium of a worm N and worm wheel 0 to periodically contact with a stationary contact member P. The electric circuit Q for the magnet F is closed by the contacts Mand P which will energize the therefore permit the switch to remain closed for an indefinite period. This is guarded against by a second switch wlnch is open during the operation of the mechanismand closes whenever said mechanism is at rest. As preferably constructed, this second controller switch comprises centrifugally operated lever arms R mounted on the shaft of the fan cscapementand which during the rotation of said shaft will move a member S longitudinally thereof so as to permit the separation of cooperating contact members T and U. On the other hand, when the rotation of the shaft ceases the lovers ll will assume a position where the member. 9 presses the contacts T and U together. This will also close the magnetic circuit and hv disengaging the detent permits the opening of the switch A.

In operation, the time mechanism may he wound by nnv suitable means (not shown), after which the switch A mav be closed and will remain closed during the interval required for the movement of the contact member M- into engagement with the contact P. hen this occurs the circuit Q will be closed. energizing the magnet F. releasing the detent latch E and permitting the spring C to throw the switch open. During the-movement the lever arm will be moved centrifugnllv to draw the memher S from the contact members '1 and U, permitting the. latter toseparate. In the normal operation of the d vice these'contact members T and U will remain separated during the entire interval in which the contact M is magnet, releasing the detent and throwing open the switch. If for any reason the upon the cessation of movement.

moving to close with the contact I, but it the movement of the mechanism is prematurely arrested the contacts T and U will be closed, which will energize the magnet, trip the latch and open the switch. It will be noted that the two controlling switches are. in parallel branches Q. and Q of the electric circuit Q, so that the closing of either one will energize the-magnet- F and release the main switch.

What'I claim as my invention is:

-l. The combination with an automatically opening switch, of a detent for holding said switch in closed position, electromagnetic means adapted upon the energizing thereof to release saiddetent, a circuit for said electromagnetic means and a time mechanism controlling said electromagnetic means acting to -automatically close the cirwith on the stopping of the mechanism, where y the electromagnetic means is energized and the detent released.

'2. The combination with an automatically opening electric switch, of a. detent for holding said switch in closed position, an electromagnet for releasing said detent, an electric circuit for said magnet, a time mechanism, and a plurality ofcircuit closers for said circuit controlled by said tifme mechanism, one operating after a predetermined movement of said mechanism and another 3. The combination with an automatically opening electric switch, of a detent for hold-' ing said switch in closed position, an :electromagn et for releasing said detent, a time mechanism, an electric circuitfor said magnet, a centrifugal mechanism driven by said time mechanism for opening inc circuit of said magnet.- when said mechanism is in mo-' tion adapted on the stopping of said mecha nism to close the circuit energizing said open the same, a latch detent for engaging with said spring arm to hold the same'in retracted position, an electromagnet adapt-- ed upon the energizing thereof to release said latch detent, a time mechanism, a circuit for said magnet and meanscontrolledby said time mechanism for energizing said magnet alternatively upon the abnormal stopping-of said mechanism or the normal completion of movement thereof.

5. The combination with an electric switch, means for automatically opening said switch, a latch detent'ior engaging said switch operating means upon the closing otthe switch and holding the same in retracted position, an elc ctromagnetfor releasing said l'atch detent, a time mechanism, a circuit for said electronnlgne't, a )lurality of circuit closers one being operated by said time mechanism after a predetermined interval, and centrifugal means operated by said time mechanism controlling-the other circuit breaker aiid adapted to close the same upon thc'stopping of the mechanism. In testimoin whereof I affix my signature inpresence 0 two witnesses.

FRANK KUHN.

' \Vitnesses: a i

\V. J..-Bm.u1\'ar, Janos I. BARRY. 

